How to use Screen & viewport inspector
Measure screen size, layout and visual viewports, pixel ratio and orientation in this tab. The check runs when you submit the form. Its inputs are processed in this browser.
How the check works
The check reads the Screen API, the layout viewport and VisualViewport when available. CSS pixels are reported separately from the device pixel ratio.
The Overview tab explains the findings. Measured data lets you search individual fields and values, while JSON report shows the complete export. Export JSON to retain a baseline, or print the findings for your own records. Review the report before sharing it: browser characteristics, token claims, and file names can reveal information about your setup.
Read the result in context
The layout viewport describes page layout. The visual viewport can shrink with zoom or an on-screen keyboard. Screen dimensions describe the exposed display, not a physical measurement in inches.
Understand the limits
Window controls, browser zoom, privacy rounding and mobile browser chrome can affect these values. Repeat after resizing to observe a change.
Common questions
Where is the input processed?
In this browser tab. This tool does not submit its input to the site server or a third-party service.
What should I keep with a result?
Record the selected options, browser and time. Review exported values before sharing them. Generated passwords, tokens and HMAC secret keys are excluded from report exports.